History of the audio connector
The audio connector as it is known today, has developed from the connectors that were used in manual telephone exchanges in the late 19th and early 20th century. That’s why the audio connector has one of the longest evolutions in the connector technology.
It is typically used to transfer audio and video signals. Back in the days it was also used to supply small electronic devices with power. Due to the high risk of shorts this is no longer used.
Construction of the audio connector
In its simplest form the connector consists of an elongated shaft and a ball-shaped, rounded tip which is separated by an isolating ring.
The audio connector knows two main specifications which differ in the diameter of the shaft: one with 3.5 mm and one with 6.3 mm diameter. The miniature size connector is often used on portable devices such as smart phones or on soundcards. The 6.3 mm connector is used on almost every device in the music industry. There are some other specifications, for example with 2.5 mm, 4.4 mm and 5.2 mm and 7.1 mm, that are not very common.
Special applications of the audio connector
The audio connector is not only differed by the shaft diameter but also by the amount of poles. There is for instance the mono plug with two poles, the three-pole stereo plug and the mono plug with symmetrical connection and three poles.
A specialty is the four-pole stereo plug with an additional function. On this plug four contacts are available. It is used to connect headsets but also to transfer multi-channel, audio, video and USB signals.
Colour coding of the 3.5 mm audio connector
Our Mini-PCs are equipped with different sockets to connect the audio plug. There are special colours to distinguish between the various specifications.
- pink: Mic-In
- blue: Line-In
- green: Line-Out
- black: Rear speaker ouput
- silver: Side speaker ouput
- orange: Subwoofer output